Now, we recall some known results of classical singular integrals and make a comparative analysis.
It was first shown by Calderón and Zygmund [1]} that the singular integrals \(T_{\Omega }\)  defined by
\(T_{\Omega }f(x)=\textrm {p.v.}\int _{\mathbb {R}^d}\frac{\Omega (y/|y|)}{|y|^d}f(x-y)dy\) 
